Dragons love nothing more than a great big pile of treasure on which to sleep. The wealthier a dragon is, the more powerful it must be, so they will go to any lengths to increase their hoard of gold. The open war between dragons that was fuelled by this lust for wealth, was destroying the realm of Dungaria, so the gods decreed for it to become a more ritualised form of combat.
As the dragons are no longer able to engage in open war with their kin, they've taken to recruiting raiders to assault the dungeons of other dragons and steal their treasure. In Dungeon Assault, you must take on the mantle of dragonhood, strengthening the protections around your hoard and sending out raiding parties of your own.